Mold



C. VUGHAN @ch 18, 192?a MOLD Original Filed Feb. '7, 1923 2 Sheets-Sheet l .L N .uw y .EE

w/ .L W slar 14, w QW @L j @w nm 4o the sprue` and in Patented Oct. 18, 1927. e

@UNITED STATES `Parri-: ia'l' oFFicE.

CONRAD 'VAUGHAN,

or CLEVELAND, oHIo, AssIGNoR 'ro 'man mailform COMPANY, or LEvnLAND, onro, A CORPORATION or omo.

MOLD.

Original application illed February 7, 1923, Serial No. 617,439. Divided and this application January 5, 1925. Serial No. 5,11.

lhis invention relates to permanent metal molds, the invention being particularly useful in forming castings of aluninum alloys or any alloys having relatively high crystalb lization shrinkage and relatively ow fusing point. t Y

This application is a division of my prior application Serial No.l 617 ,439, filed February 7, 1923, for mold and method of casting. An'object of the invention is to retardlthe conduction of heat. from that part of the mold forming the sprue cavity so that the freezing of the metal in the, sprue cavity is retarded and a smaller amount of metal. in the spiue is required for properly feeding the casting as it solidiiies in the mold cavity.

A. further'object is to provide a mold in which the metal can be poured at a'lower temperature and yet the castings will be properly fed because freezing of thevmolten metal in the sprue cavity dis retarded until i after the metal has solidified -in themold cavity. l5 Another object is to provide` a mold in which perfect castings may be made in a relatively shorterv time, due to the use of ymetal ynearer the solidification temperature and in which there will be a smaller excess of metal in the sprueA cavity..

A. further object of the invention is to rovide a mold'in which the time'yfor solidi- Ecation may be shortened by cooling por. tionsof the mold adjacent the heavier parts of the casting or the parts more remote from the sprue.

`Another object of the invention is to provide a mold in which castings may be made having a relatively small amount of metal in which the cross-sectional area of the gate is relativel small due to the shape of the casting to be made. Other objects willbe apparent from the following 'description and annexed drawlIl S.

gReference should be yhad to the accompanying drawings forming a part of this specification, inwhich Figure 1 is a vertical section through the assembled mold. Figs. 2 and 3 are vertical sections through the upper and lower mold sections, the sections1 shown in Figs. 2 and 3 being taken 'in' -a plane at right angles to that'shown in Figi.

`and extends through an opening 12 in the 75 Sled 'the lower sectionor base lfof the mold is'inthe form of a-stand with'side legs 2 and a top 3 in which the mold cavity'4 is formed. The mold cavity 4 has an open' cylindrical bottom portion 5 in which lits a plunger 6 which carries an upwardly projecting 'core 7 l' at its' upper` end. The plunger 6 has a downwardly extending stem `8 which fits in an l'(0 opening -in a cross bar 9 connecting the legs 2 adjacent their lower ends. A lever 10 is pivoted upona cross pin 11 extending between the -legs 2 adjacent one side thereof stein`8. Across pin 13 extends through the plunger 6 and serves to positively limit the upward movement of the plunger. The upper and loweredges of the opening 12 fare rounded so that'the lever 1() does not bind 80 therein when swung about its pivot. When the mold core is in operative position for casting, the pin 13 is in engagement with the bottom of the mold as shown in Fig. 1, the

lplunger .6.and core 7 being movable down- 85 I wardly from thisl position to that shown in Fig. 2 to free vthe core from the casting. The upper moldsection 14 has handles 15 by vmeans of which. it can be readily lifted off the bottom section. 1 and has a lower flange 90 16 adapted to fit within the lupper portion of -themold cavity 4.

, The mold section 14 has acentral bore 17 lwhich tapers slightly toward the bottom.

The mold section 14 is also providedwith 95 an annular air chamber 22 preferably with outside openings therein. An easy method of providing such a chamber is Yto'form a tubular liner 18 with a thin intermediate portion 21 spaced from the wall of the bore 100 1-7, and thick upper and lower edfre portions 19 and 2o fitting tightly in the iore 17.

When the moldis assembled as showniii Fig. 1, the inner bore of the liner` 18 forms the mold gate and sprue recess, the annular passage between the core 7 and the lowerL portion of the liner 18 forming the gate and the remainder of the bore the sprue recess.

To facilitatelthe removal of castings from the mold both the core 7 and the inner bore 110I` of-the liner 18 forming the sprue recess are 'gate or in the heavy sections of the casting.

This passage may follow the shape of the mold cavity and be formed in any suitable p manner as by cores when casting the mold,

or it may be formed of a rectangular shape, as shown in Fig. 7, by boring into the mold after the mold has been cast.

In operation, the mold sections will be assembled as shown in Fig. l and molten metal will be poured in at the' top until both the cavity 4 in the lower section and the sprue cavity are filled.v As the solidiication of the metal in the mold cavity takes place, additional metal is suppliedfrom the sprue cavity. It has heretofore been necessary to provide a rather large sprue recess to -maintain a sufcient reserve supply of molten metal and to have a sprue recess of a sufficient diameter that the center of the sprue ,would remain fluid long enough to supplyl the necessary 4metal to the mold cavity. The present invention, however, provides a construction for the sprue cavity which retards the loss. of the heat in the sprue and delays freezing until after the casting has hardened in the mold 4cavity and thus permits the relatively small amount" of metal in the sprue cavityto properly feed the solidifying casting. The annular lair chamber 22 surrrounding the sprue cavity retard-s the loss of heat for it decreases the volume of metal directly conducting the heat away from the sprue cavity so that themetal in the sprue may be maintained molten for a longer period of time and a relativel larger percentage of the sprue metal is avai able for feeding the casting.

That the metal for feeding the casting is drawn from sides of the sprue as well as down through the center, as is usual, is shown by the shape'of solidified sprue metal in Figs. 2 and 4, wherein the side 28 is concaved all the Way around. In Fig. 4 the casting 24 is shown in full lines and the sprue 25 in dotted lines, the casting 24 after the 4sprue is removed having a central aperturel 26.

If it is desired to hastenthe cooling and solidication of the metal in the sprueafter the casting is solidified, any suitable fluid, such as compressed air, can be circulated around the passage 22 through' the openings 30, thus greatly reducing the time of wa1t1ng after the casting is solidified and until the sprue is sufficiently solidified to removel the core 7 It will thus be seen that by varying the size of the annular passage surrounding the sprue cavity, the length of time that the sprue metpal may be held in molten condition can be varied. Also by varying the temperature or quantity of vfluid supplied to the body of the mold, the cooling time of the casting itself may be varied. Also by the circulation of air through the annular passage 22 surrounding the sprue cavity, the time of'solidification of the sprue after the casting is solidified may be decreased so that the core may be removed more quickly. By providing these variables it is possible to design molds for many shapes of Casting which will greatly increase the production yield per mold per day, for provision can be made vfor removing heat as fast as desirable from the heavier sections of the castings 'the metal in the sprue a relatively less amount of metal is necessary for properly feeding the casting for a relatively larger percent of the metal in the sprue is available for this purpose.V It will thus be seen that castings may be made according to this invention in which the gate is of relatively small cross sectional area or in which all parts of the gate are relatively narrow, so that the tendency to form pipes is prevented and the 'character of the metal in the casting is` improved.

Furthermore,- it is to be understood that the particular forms of apparatus shown and described, and the particular procedure Set forth, are presented for purposes of explanation and illustration andthat various modilicatios 0f said apparatus and procedure can be made without departing from my vinvention as defined in the appended claims.

What I claim is:

1. A permanent mold for casting metallici,v

alloys of relatively high crystallization shrinkage and a relatively low fusing pointl fluid to accelerate the cooling of said heavier casting sections, and means to retard the escape of heatfrom metal in the sprue cavity so that the metal in the mold cavity will v solidify before the metal in the sprue cavity.v

3. In a permanent mold for casting aluminum alloys and the like, in combination, a mold cavity for a casting of non-uniform section, a sprue cavity and a relatively small gate between and communicating with said sprue cavity and mold cavity, means to cool the mold adjacent the heavier sections of the casting to accelerate the cooling of said heavier casting sections, and means to retard the escape of heat from metal in the sprue cavity so that the metal in the mold cavity will solidify before the metal in the sprue cavity.

4. In a permanent moldfor casting aluminun alloys and the like, in combination, a mold cavity for a casting of non-uniform section, a sprue cavity, and a relatively small gate between and communicating with said sprue cavity and mold cavity, and means to retard the escape of heat from metal in the sprue cavity so that the metal in the mold cavity will solidify before the metal in the sprue cavity.

5. Ina permanent mold for casting aluminum alloys and the like, in combination, a mold cavity, a sprue cavity, and a relatively small gate between and communicating with said sprue cavity and mold cavity, means to retard the escape of heat of metal in the sprue cavity so that the metal in the mold v cavity will solidify before the metal in the sprue cavity, and means to chill the metal in the sprue cavity after the metal in the mold cavity Vhas solidified.

In testimony whereof, I hereunto affix my signature.

CONRAD VAUGHAN. 

